大兴安岭中段哈达陶勒盖组火山岩U-Pb定年及成因  

Zircon U-Pb Dating and Petrogenesis of Volcanic Rocks in Hadataolegai Formation,Middle Great Xing'an Range

作　　者：司秋亮[1,2] 王恩德[1] 唐振[2] 马永非[2] SI Qiu-liang;WANG En-de;TANG Zhen;MA Yong-fei(School of Resources&Civil Engineering,Northeastern University,Shenyang 110819,China;Shenyang Center,China Geological Survey,Shenyang 110034,China)

机构地区：[1]东北大学资源与土木工程学院,辽宁沈阳110819 [2]中国地质调查局沈阳地质调查中心,辽宁沈阳110034

出　　处：《东北大学学报（自然科学版）》2018年第12期1779-1782,共4页Journal of Northeastern University(Natural Science)

基　　金：大兴安岭成矿带突泉-翁牛特地区地质矿产调查(DD20160048);内蒙古1:5万五家户等五幅区域地质调查(DD20160048-03)

摘　　要：为了研究大兴安岭中段哈达陶勒盖组火山岩的形成时代和岩石成因,进行了锆石U-Pb同位素年龄测试和地球化学研究. LA-ICP-MS锆石U-Pb定年结果显示,哈达陶勒盖组火山岩形成于234～244Ma的中三叠世.岩石地球化学研究表明,哈达陶勒盖组火山岩具有低硅富碱、富钙镁的特征;稀土丰度总量w(∑RE)=122. 32×10-6～140. 66×10-6,轻、重稀土分馏较明显,m(La)/m (Yb)N=11. 99～18. 68,无明显Eu负异常(δEu=0. 84～0. 98),微量元素以富集Rb,K,Ba,Th,亏损Nb,P,Ti为特征.哈达陶勒盖组火山岩岩浆源区为富集的岩石圈地幔,并遭受了地壳物质的混染.Zircon U-Pb isotopic dating and geochemical analysis were used to study the formation age and petrogenesis of the volcanic rocks in Hadataolegai Formation,the middle Great Xing’an Range.LA-ICP-MS dating results show that the volcanic rocks in Hadataolegai Formation formed in Middle Triassic from 234 Ma to 244 Ma.The geochemical study suggests that the volcanic rocks are poor in silicon,rich in alkalis,calcium and magnesium.The total RE amount ranges from 122.32×10-6 to 140.66×10-6.Fractionation of LRE and HRE is obvious[m(La)/m(Yb)N=11.99~18.68]and Eu has no anomalies(δEu=0.84~0.98).The trace element geochemistry are characterized evidently by enrichment of Rb,K,Ba,Th,and depletion of Nb,P,Ti.Original magma of the volcanic in Hadataolegai Formation is chiefly derived from enriched lithospheric mantle,and contaminated by crustal material.

关 键 词：锆石U-PB年龄 地球化学 哈达陶勒盖组 火山岩 大兴安岭中段 

分 类 号：P588.141[天文地球—岩石学] P597.3[天文地球—地质学]